Move addFSDA2path.m into /toolbox

[bpancras]

This is a symbolic task highlighting the completion of the reorg.

[AldoCorbelliniUNIPR]

Like we already pointed out in step 8, (Inside CreateFSDAhelpFiles.m the variable 'FSDAroot' is pointing to the folder where 'addFSDA2path.m' lives, so moving 'addFSDA2path' to the '/toolbox' folder should not disrupt the functionality of the code.) we add that this file relocation implies that now 'CreateFSDAhelpFiles.m' and 'runAllMyTestsFS.m' should work properly.